Screw-cutting machine.



R. G. NUGENT.

SCREW CUTTING MACHINE. APYLIOATION FILED H113A 1o, 1908.

94:29? l Patented Dec. 7, 1909 3 SHEETS-SHEET 1.

R. C. NUGENT.

SGREW CUTTING MACHINE.

Y APPLICATION FILED FEB.10, 1908, 942,791 A Patented Dec. 7, 1909.

3 SHBETSf-SHEET 2.

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R. C. NUGENT.

' SCREW CUTTING MACHINE.

APPLICATION FILED PEB. 1o, 190s.

Patented Dec. 7, 1909.

BSHEETS-SHEBT 3.

UNITE@ STATES PATENT FFIQF.

RICHARD C. NUGENT, OF CINCINNATI, OI-IIO, ASSIGNOR TO THE NUGENT TOOLCOMPANY, OF CINCINNATI, OHIO.

SCREIV-CUTTING MACHINE.

Application filed February 10, 1908.

To all whom it may concern:

Be it known that I, RICHARD C. NUGENT, a

citizen of the United States, residing at Cincinnati, in the county ofHamilton and State of Ohio, have invented certain new and usefulImprovements in Screw-Cutting Machines, of which the following is aspecilication.

' My invention relates to improvements in screw-cutting machines, andrefers in particular to a device adapted for application to monitorlathes and the like machines for threading different kinds of work.

One object of my invention is the provision of a thread cutting machinewhich may readily be adapted for various kinds of work and which whenthe proper length of screw threads have been cut will be automaticallyopened to release the work from the dies.

Another object of my invention is the provision of a screw cuttingdevice of strong, simple and practical construction, which is adjustableas to all its parts so as to give a wide range of usage, and which willhe efficient for all purposes.

`With the above and other objects in view, my invention comprises a heador supporting member, aws slidably mounted therein and carrying coactingdies or cutters, means tending to force the jaws apart and a latch tolock the jaws set or closed, and an adjustable member adapted to becontacted by the work to release the latch and allow the jaws to bespread or opened.

My invention further consists of a device of the character set forthembodying cert-ain other novel features of construction, combination andarrangement of parts substan tially as disclosed herein and asillustrated in the accompanying drawings, in which :c

Figure 1 is a front or face view of my improved screw cutting device.Fig. 2 is a rear end elevation of the same. Fig. 3 is a longitudinalsectional view of the invention taken in a vertical plane. Fig. 4t is abroken sectional view of the head. Fig. 5 represents a longitudinalsectional view of the device taken on a plane at right angles to that ofFig. 3.

In the drawings: the numeral 1, designates the shank or spindle of thedevice by means of which it is usually applied to a lathe or other metalworking machine. The shank has a transversely disposed head or support-Specicaton of Letters Patent.

Patented Dec. 7, 1909.

serial No. 415,113.

ing member 2, at its forward end, and the head has an open grooveway 8,therein to receive the slidable jaw members 4. The base of the groovewayis widened out as at 5, to receive the complementary ribs 6, on the jawslides so as to prevent displacement of the slides while allowingtransverse sliding movement thereof. The opposing inner ends of theslides are concaved as at 7, so as to correspond to the bore 8, in thehead and shank of the device. Pins or bolts 9, extend from the back ofthe jaw slides through elongated openings 10, in the rear face of thehead, and the extended plain portion of the bolts also pass through theeccentric slots 11, in the annular aw closing member 12. rlhis jawclosing member or eccentric plate is rotatably confined on the plainportion of the shank resting against the rear face of the head. Nuts 18,on the outer threaded ends of the bolts hold the eccentric plate inposition, and washers 14, serve to i'educe friction between the nuts andthe surface of the plate and also prevent loosening of the nuts. Radialpockets 15, are formed in the head parallel to the grooveway therein andspiral springs 16, are confined in said pockets and bear against theinward side of the pins on the slides, thereby tending to force theslides outward and apart. Set screws 17, are entered through the outerends of the head in line with the spring-receiving pockets to serve asabutments for the bolts or pins on the back of the slides, to limit theoutward throw of the slides. The eccentric plate is provided with ahandle 18, by means of which the plate may be given a partial rotationto force the slides toward each other against the tension of the coilsprings.

A sleeve or thimble 18, having a closed rear end 19, is loosely conlinedin the bore of the head and shank, and an internal shoulder 20, isprovided in the bore of the sha-nk to limit the inward movement of thesleeve. The sleeve has a transverse opening 21, therethrough to receivethe transverse key 22, which plays in the elongated slot or opening 23,formed transversely through the shank. This key is secured in the sleeveby means of the set screw 24, in the end wall of the sleeve whichengages a seat or, recess 25, in the edge of the key. The shank of thebolt 26, is received in the sleeve and is secured at any adjustedposition therein by means of the set screw 27, which set screw isreceived in and passes up through the slot 28, in the die head so as tobe readily accessible for adjusting the bolt 26. This bolt has a head29, at its outer protruding end which carries the transverse stop piece30, which is adapted to be contacted by the work after the threads havebeen cut thereon. A latch member 31, is seated in the tangential slot orgroove 32, on the back of the eccentric annulus, and is adjusted thereinby means of the screw 33, which bears'on the end of the latch, and thelatch is held in the adjusted position by means of the clamping screws34, which bear in the longitudinal slots 35, formed in the body of thelatch. The latch has a lug 36, on the face thereof adapted to be engagedby and interlock with'the key to lock the annulus to hold the jawsclosed, and the corresponding inactive edges of the lug and key arebeveled as at 37, to cause the key to ride up over the lug and interlockwith the same when the annulus is rotated to close the die. rlhe spring39, in the bore of the spindle or shank bears against the closed end ofthe sleeve therein, thereby holding the key in engagement with the latchand forcing the stop piece to the outermost position. The spring is heldin the bore by means of the screw bolt 40, and the tension of the saidspring may be adjusted by means ofthis screw. Jaw blocks 4l, are carriedby each of the slides and are secured to the slides by means of screws42, or other suitable fastenings. The slides preferably project slightlybeyond the face of the head block and the jaws are each channeled to litdown over the edge of the slides as shown, so that there is no danger oftwisting the jaws upon the slides.

The opposing faces of the jaws are radially countersunk at 46, toprovide plenty of clearance for the work, and radial grooves 47, areprovided in the jaws diverging outwardly from the countersunk innerportion thereof, in which the cutters or dies 4S, are seated. Thecutters are each provided with a shoulder 49, along one edge upon whichthe heads of the securing screws 50, bear, and in this way the cuttersare held in their seats and clamped in their adjusted position. Theheads of the securing screws are thus countersunk in the material of thejaws and the surface of the jaws are not broken by any protruding parts.rIhe cutters are ad justed by means of the set bolts 51, which bear uponthe ends of the cutters, and as an aid to the proper adjustment of thecutters they may be each provided with a notch 52, adapted to registerwith the corresponding circular mark 53, on the face of the jaws.

In operation, the spindle of the die is placed in the head stock or tailstock of the lathe, according as to whether' the die or the work is tobe revolved, or it may be mountedupon any other machine of a likecharacter. The jaws being closed, the work is acted upon by the cuttersuntil the desired length of cut has been made, and the stop piece is soadjusted that at the end of such cut, the st-op piece is contacted bythe work and is forced inward against the tension of the spring in thebore of the spindle. This inward movement of the stop piece frees thekey from engagement by the latch and the eccentric annulus is then freeto revolve. The springs in the head then force the slides outward andthis movement causes a partial rotation of the annulus by reason of t-heeccentric connection with the slides. The jaws are now open and the workmay be readily removed. To close the jaws to the set position, theeccentric annulus is given a twist backward which draws the jawstogether again and the key then interlocks with the latch member andlocks the part set. The depth of the threads may be governed byadjusting the cutters in their radial seats, and the length of the cutor threaded portion is regulated by adjusting the stop piece outward orinward according to requirements. If so desired, instead of using thedie as a machine tool, it may be used as a hand tool by providing a pairof handles for the head, by means of which the die may be rotated uponthe work.

From the foregoing description taken in connection with the drawings itwill be evident that I have produced an automatic collapsible die whichis thoroughly practical, and which accomplishes all the objects hereinaimed at.

I claim:

l. A collapsible die comprising a spindle and a head carried thereby,the head having a grooveway therein, die supporting slides held in saidgrooveway, pins carried by the slides and projecting rearwardly throughslots in the head, pockets being formed in the head and springs seatedin said pocket-s bearing against the slide pins to force the slidesapart, abutment screws to be engaged by the pins to limit the openingmovement of the slides, an annulus mounted on the spindle in rear of thehead having cam slots receiving the slide pins, a latch on the annulus,an adjustable stop member mounted in the bore of the spindle, atransverse key carried by the same to engage the latch on the annulus tolock the annulus and hold the slides closed, a spring adjustably held inthe bore of the spindle to hold the key in engagement with the latch,and cutters adjustably mounted on the slides.v

2. A die comprising a head having a grooveway therein, die supportingslides held in the grooveway, pins on the slides projecting rearwardlythrough the head, springs seated in the head and bearing out- 'Wardlyagainst the heads to force the slides gagement With the latch, andcutters mountl0 outward, abntments to be engaged by the ed in theslides.

pins to limit the outward movement of the In testimony whereof I aHX mysignature, slides, an annnlus rotatably mounted n real' in presence oftwo Witnesses.

of the head and having Cam slots reeevno' the pins, a latch membelcaried by the anb- RIGHARD C' NUGENT' nulus, an adjustable stop mountedin the head, a key carried by the Same to engage the latch, a spring tohold the key in enl VVt-nesses JAMES I. STEPHENSON, PAUL B. MARFIELD.

